WESTFIELD, Ind. -- The desire to coach, to teach defensive players his tomahawk chop and to “hate” quarterbacks still burns for former Indianapolis Colts pass-rush specialist Robert Mathis.

But Mathis also missed being able to spend more time at home, where he would be able to tell his kids good night on a regular basis.

He had to make a decision: Continue to serve as a pass-rush consultant for the Colts or spend more time at home with his family?

Colts All-Time Sacks Leaders

Robert Mathis is the Colts' all-time leader in sacks, a stat that wasn't tracked until 1982.

Player

Years

Sacks

Robert Mathis

2003-16

123.0

Dwight Freeney

2002-12

107.5

Duane Bickett

1985-93

50.0

Donnell Thompson

1981-91

40.0

Chad Bratzke

1999-2003

37.0

Pro Football Reference

Mathis, thanks to a conversation he had during his retirement party two years ago with former teammate Dan Muir, will be able to continue to do both. He just had to change job titles.

Mathis, who had a team-record 123 sacks in his 14-year career, is still doing what he’s passionate about in teaching pass-rush moves, but he’s doing it a different way. He resigned from the Colts to join forces with Muir at a sports-performance facility called Pro X. It's right next door to the Colts' training facility, about 30 minutes north of Indianapolis.

“The Colts have done a great job supporting me,” Mathis said inside the state-of-the-art facility that features a training room, football field, baseball diamond and several batting cages. “I’m still a partner with them. I’m just not a coach with the team anymore. They know my heart is in a good place, know I have good intentions and that I want the best for them. This is one of the ways I feel like I can help them.

“It’s a win-win because I still get to do what I’m passionate about in teaching while helping guys on the team I spent my entire career with. Everything is legal. There’s no gray area. I’m ecstatic about it and so are the Colts.”

Colts coach Frank Reich understood Mathis' desire to spend more time at home.

"I just think that Robert wanted to step down and kind of focus on [family] a little bit but still consult with us a little bit," Reich said. "We just want to have a little piece of him every now and then. It’s a big jump to go from playing to coaching; it’s a big commitment. So I just think it can be a win-win where he’ll be doing his thing there, but he can still offer his wisdom and stuff to us at appropriate times and in appropriate ways.”

Robert Mathis never envisioned himself as a coach, but he's developed a passion for it. Zach Bolinger/Icon Sportswire

The NFL’s collective bargaining agreement limits the amount of time an assistant coach can train athletes during the offseason. By opening the academy, Mathis can work with them more.

“You can’t touch players after the offseason workouts and minicamps and things like that,” Mathis said. “That’s like the most critical five weeks between then and training camp. It can make or break a season. It’s fine for vets, but it’s still a developmental time for rookies up to like fifth-year guys. Those guys need work. From the time of their last game until training camp, that can be almost six months of not touching an O-lineman. That’s a long time.”

The goal for Muir, who played in the NFL for seven years, including four as Mathis’ teammate with the Colts, is to have athletes stay in Indianapolis instead of going to training facilities in states such as Florida, California and Arizona because they have everything here -- minus the year-round warm weather.

Former Colts long-snapper Justin Snow, offensive lineman Donald Thomas and cornerback Marlin Jackson are also part of the training group.

“It’s not about coaching -- it’s about teaching,” Muir said. “You see a guy and say if he can get one or two more things, he can dominate. I want to get my hands on them.”

About half of the defensive line is working out with Mathis and Muir. On one March day, second-year defensive end Kemoko Turay was in attendance. The range of drills included mobility stretching, swim moves to get around Thomas and Muir and speed drills around cones to get to the quarterback.

“I’m teaching every one of my moves every chance I get,” Mathis said. “There’s no bones about it. I love teaching pass-rushers and I hate quarterbacks. Any chance I get to body slam, I will on any level. [Colts defensive coordinator Matt] Eberflus and [defensive line coach Mike] Phair taught me some valuable lessons last year as a coach. Details. The little things that turn out to be the big things and how they transformed the defense.”

Turay worked closely with Mathis during his rookie season, from film sessions to extra work before and after practice, to boxing-type drills to work on Turay’s hand speed.

“Rob sat me down as soon as I was drafted and told me about the potential I have,” Turay said. “It could be utilized to be perfected. I didn’t get enough time with him during the season, but now I’m able to train with him, try to take his skill set and learn from him all the things he wants to teach me. He knows the game. For me to be able to train with him is an honor. It’s good for him to start his own training facility.”

Of course, this is the same Robert Mathis who stood behind the podium and said he had zero interest in coaching the day he announced his retirement in December 2016.

“Things change,” Mathis said, laughing. “My kids don’t know what to do with themselves when they see daddy before bedtime. I love being a coach, love being around my team because I honestly feel like that’s my team. But keeping things in perspective, life goes on. You keep those relationships strong, keep those bridges together, and it pays off in the end.”